Health News: Rethinking A Healthy Diet

by Admin EditorNovember 17, 2018

Two to three decades ago recommendations for a high-quality diet to avoid cardiovascular disease were developed in high-income countries and they didn’t consider other parts of the world or how diets have changed. Scientists with the Population Health Research Institute of McMaster University and Hamilton Health Sciences are using research from several large global studies to develop an updated, international approach of identifying a healthy diet.

“A high-quality diet associated with a lower risk of cardiovascular disease and death has higher amounts of fruit, vegetables, nuts, legumes, fish, dairy and meats,” says co-principal investigator Andrew Mente, a researcher of PHRI and associate professor of health research methods, evidence and impact at McMaster. “We see that what people eat, such as dairy and meat, differ in the global population, and the recommendations must consider populations whether what they eat is either low or high.”

“Our results are based on data involving populations from over 50 countries and so are more likely to apply to people around the world, better than recommendations based on studies conducted in a single country,” added co-principal investigator and PHRI investigator Mahshid Dehghan.

The investigators research combines information from several international studies led by PHRI and involving about 240,000 people from more than 50 countries. These includes studies with more than 138,500 people aged 35 to 70 without cardiovascular disease; 31,500 patients with vascular disease; 27,000 patients who have had a first heart attack, and 20,000 people who have had a first stroke.

“Currently a healthy diet is based largely on studies conducted decades ago and performed in mostly high income countries,” added Salim Yusuf, senior author and director of the PHRI “In these countries, the major problem is excessive intakes of some nutrients and some foods whereas in other countries, such as low and middle income countries, inadequacy of intake of some key foods and nutrients is the major problem. We need to identify the optimal level of intake of foods, and use such information in guiding global recommendations on diet.”

Can Healthy Diet Depend On Your Genes?

A recent Cornell University study describes how shifts in the diets of Europeans after the introduction of farming 10,000 years ago led to genetic adaptations that favored the dietary trends of the time. Before the Neolithic revolution that began around 10,000 years ago, European populations were hunter-gatherers that ate animal-based diets and some seafood. After the advent of farming in southern Europe around 8,000 years ago, European farmers switched to primarily plant-heavy diets. The study is the first to separate and compare adaptations that occurred before and after the Neolithic Revolution. It reveals that these dietary practices are reflected in the genes of Europeans. "The study shows what a striking role diet has played in the evolution of human populations," says Alon Keinan, associate professor of computational and population genomics and the paper's senior author.

The study has implications for the growing field of nutritional genomics, called nutrigenomics. Based on one's ancestry, clinicians may one day tailor each person's diet to her or his genome to improve health and prevent disease. It also shows that vegetarian diets of European farmers led to an increased frequency of an allele that encodes cells to produce enzymes that helped farmers metabolize plants. Frequency increased as a result of natural selection, where vegetarian farmers with this allele had health advantages that allowed them to have more children, passing down this genetic variant to their offspring.

The FADS1 gene found in these vegetarian farmers produces enzymes that play a vital role in the biosynthesis of omega-3 and omega-6 long-chain polyunsaturated fatty acids – also called LCPUFAs. These LCPUFAs are crucial for proper human brain development, controlling inflammation and immune response. While omega-3 and omega-6 LCPUFA can be obtained directly from animal-based diets, they are absent from plant-based diets. Vegetarians require FADS1 enzymes to biosynthesize LCPUFA from short-chain fatty acids found in plants - roots, vegetables and seeds.

Link Between Diet, Health And Genetic Variation

Analysis of ancient DNA revealed that prior to humans' farming, the animal-based diets of European hunter-gatherers predominantly favored the opposite version of the same gene, which limits the activity of FADS1 enzymes and is better suited for people with meat and seafood-based diets. Analysis of the frequencies of these alleles in Europeans showed that the prevalence of the allele for plant-based diets decreased in Europeans until the Neolithic revolution, after which it rose sharply. Concurrently, the opposite version of the same gene found in hunter-gatherers increased until the advent of farming, after which it declined sharply.

The researchers also found a gradient in the frequencies of these alleles from north to south since the Neolithic Era, including modern-day populations. All farmers relied heavily on plant-based diets, but that reliance was stronger in the south, as compared to northern Europeans whose farmer ancestors drank more milk and included seafood in their diet. Plant-based alleles regulate cholesterol levels and have been associated with risk of many diseases, including inflammatory bowel disease, cardiovascular disease, arthritis and bipolar disorder. "I want to know how different individuals respond differently to the same diet," added Kaixiong Ye, a postdoctoral researcher in Keinan's lab and the paper's lead author. “Future studies will investigate additional links between genetic variation, diets and health, so that "in the future, we can provide dietary recommendations that are personalized to one's genetic background."

Improving Health And Longevity

Increasing time between meals made male mice healthier overall and live longer compared to mice who ate more frequently, according to a new study published in Cell Metabolism. Health and longevity improved with increased fasting time, regardless of what the mice ate or how many calories they consumed, reports scientists from the National Institute on Aging (NIA) at the National Institutes of Health, the University of Wisconsin-Madison, and the Pennington Biomedical Research Center, Baton Rouge, Louisiana. "This study showed that mice who ate one meal per day, and thus had the longest fasting period, seemed to have a longer lifespan and better outcomes for common age-related liver disease and metabolic disorders," says NIA Director Richard J. Hodes, M.D. "These intriguing results in an animal model show that the interplay of total caloric intake and the length of feeding and fasting periods deserves a closer look."

The scientists randomly divided 292 male mice into two diet groups. One group received a naturally sourced diet that was lower in purified sugars and fat, and higher in protein and fiber than the other diet. The mice in each diet group were then divided into three sub-groups based on how often they had access to food. The first group of mice had access to food around the clock. A second group of mice was fed 30 percent less calories per day than the first group. The third group was meal fed, getting a single meal that added up to the exact number of calories as the round-the-clock group. Both the meal-fed and calorie-restricted mice learned to eat quickly when food was available, resulting in longer daily fasting periods for both groups.

Increasing Fasting Times

The scientists tracked the mice's metabolic health through their lifespans until their natural deaths and examined them post-mortem. Meal-fed and calorie-restricted mice showed improvements in overall health, as evidenced by delays in common age-related damage to the liver and other organs, and extended longevity. The calorie-restricted mice also showed significant improvement in fasting glucose and insulin levels compared to the other groups. Interestingly, the researchers found that diet composition had no significant impact on lifespan in the meal-fed and calorie-restricted groups.

Scientists have studied the beneficial effects of caloric restriction for more than a century, but the impact of increased fasting times has recently come under closer scrutiny, according to the study's lead author, Rafael de Cabo, Ph.D., chief of the Translational Gerontology Branch of the NIA Intramural Research Program. "Increasing daily fasting times, without a reduction of calories and regardless of the type of diet consumed, resulted in overall improvements in health and survival in male mice," said de Cabo. "Perhaps this extended daily fasting period enables repair and maintenance mechanisms that would be absent in a continuous exposure to food."

The findings are encouraging for future studies on how these types of time-restricted eating patterns might help humans to maintain healthy weight and reduce some common age-related metabolic disorders. Next steps for this research include expanding these findings to other strains of mice and other lab animal species using both sexes, and to find the potential translation of the findings in humans.

Health Tips For Men

Medical professionals from the University of Alabama at Birmingham have provided a few tips to help men get healthy. More than 12 percent of men age 18 and older are in fair or poor health leading to obesity, hypertension and even mortality, says the Centers for Disease Control and Prevention. Americans spend more than $20 billion per year on multivitamins, but not every vitamin is appropriate for every person.

“For the average person, there is no evidence that multivitamins improve health or help one avoid disease,” says William Curry, M.D., professor in the UAB School of Medicine. “There is no proven value of multivitamins unless a man has a known deficiency or specific condition. However, the doses of various vitamins - vitamins A, B complex, C, D and E - in the standard multivitamin products are typically in a safe range.” Curry recommends a multivitamin for those with malabsorption of the gut, alcoholism, previous gastric bypass surgery, severe kidney disease, on dialysis, or rare metabolic defects. Those who follow a strict vegetarian diet should also consider a general multivitamin.

Antioxidants including vitamin A, beta-carotene, and vitamins C and E are heavily promoted and advocated but studies have not found benefit for preventing cardiovascular disease or cancer, Curry says. Men with higher risk for cardiovascular disease, especially heart attack and stroke, may consider a vitamin with anti-oxidants. However, high doses of vitamin A can result in fractures and visual problems. High doses of vitamin E - 400 units per day or more - may cause higher mortality. “Vitamin E can interact with blood thinners to increase their effects,” Curry said.

Heart And Brain HealthRegular physical exercise is recommended to keep your cardiovascular system and brain healthy. Exercise helps lower blood pressure, improve lipid profile, and better control and possibly prevent Type 2 diabetes, as well as provide a longer life. “A healthy exercise program keeps the heart, lungs and blood vessels working at their best,” says David Geldmacher, M.D., director of the UAB Division of Memory Disorders. “We recommend two-and-a-half hours of moderate exercise per week, like brisk walking, or lesser totals of more intense exercise.”

The brain gets about 15 percent of the total blood output from the heart, and consumes 20 percent of the body’s oxygen although it represents only about two percent of the total body weight. It is recommended to keep the delivery systems working at their best with exercise. Research studies indicate that persistent exercise triggers hormonal pathways that actually help brain cells increase the number of connections with other cells, as well as strengthen the chemical mechanisms of memory. A combination of resistance or strengthening exercise with endurance exercise is ideal for heart and brain health.

“The time to act is now, while the brain is healthy,” Geldmacher said. “Nowhere in the neurosciences are we able to get the brain to grow new, functioning neurons. However, brain-protective mechanisms, like exercise, get their best shot to work a little bit at a time over long periods. Those with medical issues should maintain regular checkups for blood pressure, cholesterol and diabetes using medications as prescribed to keep those numbers in the healthy range.”

Tobacco RisksQuitting smoking or chewing tobacco can be very challenging, but can be beneficial for heart and lung health. It is a preventable driver of mortality through cancer and cardiovascular disease. Studies have shown that smokers are at a higher risk of having a reduced sperm count and lower sperm motility, affecting male fertility. Side effects are worse in moderate or heavy smokers. In addition to the overall issues with tobacco, chewing tobacco poses a risk for throat and neck cancer, as well as many dental problems. “Those who stop smoking will see an immediate impact on their blood pressure with a decrease within minutes, and the toxic levels of carbon monoxide decrease within a day,” said J. Michael Wells, M.D., assistant professor in UAB’s Division of Pulmonary, Allergy and Critical Care Medicine. “Within three months, lung function begins to improve, and the risk of stroke and other cardiovascular diseases will decrease by at least four times.”

A multifaceted approach is recommended, including counseling and sometimes medication. The most important thing to kicking the habit is being ready to do so. If you are not motivated to quit, you probably will not succeed. Set a stop date. Get rid of paraphernalia lying around the house such as ashtrays, lighters and cigarettes. Avoid stopping at the store where you typically purchased your tobacco products. Don’t be afraid to lean on a family member or friend. Kick the habit with a friend who is ready to quit also. Find a support group. Use nicotine replacement products. “Don’t be afraid of failure,” Wells added. “If you have a relapse, pick yourself up and try again. Cessation for any amount of time is a success. If it were easy, we wouldn’t be having this conversation.”

Drinking RisksKidney stones is a multifactorial disease influenced by events in the kidney, gastrointestinal system and bone health, certain endocrine disorders, genetics, diet, and environmental factors. Around 11 percent of men will be affected by kidney stones sometime in their lives. “Warmer climates may cause individuals to perspire excessively, causing them to become dehydrated,” says Dean Assimos, M.D., chair of the UAB Department of Urology. “This results in urine becoming concentrated and the chemicals forming kidney stones. Crystals of these chemicals can arise, which is a prerequisite for kidney stone formation. The more fluid you consume, the less likely you are to have kidney stones, but it is important to consume the right fluids.”

Drink 10 to 12 ounces of water every couple of hours while you are awake. If you are exercising or perspiring, drink more due to losing these fluids more rapidly. Sugary drinks that include high levels of fructose corn syrup, like sodas, should be avoided. Studies have shown a correlation between drinks with high fructose and kidney stones, as well as links between obesity and kidney stones. “The consumption of coffee, tea, beer and wine in moderate amounts has been associated with reduced risk of developing kidney stones in epidemiology studies,” Assimos added.

It is recommended to not drink anything other than water or black coffee. Soft drinks contain sodium and sugar or artificial sweeteners, which may contribute to obesity and diabetes. Carbonation causes calcium to be pulled from bones into the blood stream, which causes osteoporosis and kidney stones. Sports drinks often contain more sodium than you should eat in a day. “Alcohol is another ‘simple’ sugar and is burned before other calorie sources, more likely to lead to diabetes and obesity,” says UAB nurse practitioner Jody Gilchrist. “Alcohol should be limited to one to two servings a day. High amounts of alcohol lead to poor judgment and eating more unhealthy foods.”

Excessive alcohol use can be a cause of sexual dysfunction, because it can lead to decreased testosterone, decreased libido and difficulty getting an erection. It is also important that a man with erectile dysfunction not drink too much alcohol while using certain medications for erectile dysfunction, as the combination can cause an unsafe drop in blood pressure and impair the ability of the medication to work.

Fruit And Veggie HealthHeart health, diabetes and hormones levels are tied to maintaining a proper diet, including eating the daily recommended fruits and vegetables. The most important thing a man can do for his overall health is eat a healthy diet. Many of the books and courses for complicated diets have sustained benefit for the average man. Extremely low-fat diets may be dangerous, because the fats are replaced by more carbohydrates, usually simple sugars, which have a variety of bad effects, including Type 2 diabetes. “Moderate restriction of sodium is a good idea,” Curry said. “Processed foods and snacks are usually loaded with it, as are canned vegetables and soups unless labeled low in sodium.”

He recommends the DASH diet as a reliable model that is affordable and tasty due to its reduction in sodium and variety of foods rich in nutrients. The Mediterranean Diet and its variations also can be worked into a healthy approach to dieting, according to a recent UAB study. Both diets have been associated with maintaining brain health as well. The production of testosterone and proper urinary function can also be tied to a healthy diet. The best time to start eating a healthy diet is when one is young. It helps set the stage for eating healthy throughout life, and can prevent problems that come with poor eating choices.

Protecting Your SkinUltraviolet radiation from the sun directly damages the skin DNA in susceptible people. Over time, this damage can build up, leading to the formation of cancerous cells, which grow into tumors. Know the types of skin cancer and what they look like to help better identify markings that may have you concerned. Three common types of skin cancer are basal cell carcinoma, squamous cell carcinoma and melanoma. “Skin cancer, like all types of cancer, is capable of destroying healthy tissue and spreading to distant body sites,” says C. Blake Phillips, M.D., a fellow in the UAB Department of Dermatology. “If undetected or untreated, skin cancers lead to loss of vital functions or death. It is important to keep an eye on your skin and watch for changes that could be a sign of skin cancer.”

The most important aspect of protecting your skin is to avoid UV radiation exposure from the sun. Wear sunscreen with an SPF value of 30 or higher every day to exposed areas. Look for products that don’t feel greasy, and block both UVA and UVB. Wear protective clothing and wide-brimmed hats with sunglasses when out in the sun. Avoid peak sun hours of the day from 10 a.m. to 5 p.m., choosing to do outdoor activities in morning or evening hours. Avoid indoor tanning, and choose pigmented lotion, spray tan or no tan instead.

Family Health HistoryNext to skin cancers, prostate cancer is the most common cancer diagnosed in American men. Men age 50 and older should be screened during their annual physical exam with a discussion regarding prostate cancer risk. A routine blood test can measure a biomarker called prostate-specific antigen or PSA, which can identify a man’s risk of prostate cancer along with a digital rectal exam. Concern based on the PSA blood test level or digital rectal exam can prompt a biopsy of the prostate gland, which can be further evaluated to determine the presence of prostate cancer and, if found, the aggressiveness of the cancer.

“Many men do not know their family history of prostate cancer because men tend not to talk about their health concerns, even with their children and other family members,” says Soroush Rais-Bahrami, M.D., assistant professor in the UAB Department of Urology. “It is important to discuss family history due to the significantly higher risk for men with a first-degree relative who has been diagnosed with prostate cancer.” Certain men may have a higher risk of prostate cancer based on family history or ethnicity, race, and ancestry and should receive their first screening discussions at the age of 40.